The invention relates to a blower with a housing encasing same and/or with a duct system adjoining same, an open-pore foam material preferably sealed by a skin toward the source of the noise being provided locally for noise reduction, this foam material being utilized as the sole means to form the wall of the housing and/or of the duct system.
A blower of such a construction, arranged in the zone of the radiator of an internal combustion engine and comprising an impeller surrounded by foam material and having a free air outlet adjacent to the noise damping means is disclosed in German Published Unexamined Patent Application (DE-OS) No. 2,506,364.
In automobile heating systems a supporting function is also carried out by the housing accommodating the blower which latter can be operated at varying rotational speeds. This blower housing represents a part of a heater box equipped with attachments and installations as well as a duct system. It is, therefore, an object of the invention to utilize the measures for noise damping known from DE-OS No. 2,506,364 in such an integrated blower, without impairing the supportive properties during normal driving operation and without incurring an intolerable extra amount of weight.
For this reason, a blower of the type discussed above is proposed according to the invention, wherein the foam material is respectively supported and marginally bordered by wall sections of the housing and/or of the duct system and wherien these wall sections constitute a skeleton whcih, at least during normal driving operation, is dimensionally rigid and supportive, this skeleton serving for the accommodation of installation components, operating parts, and mounting elements.
A supporting ability adequate in normal driving operation coupled with a crash characteristic which is advantageous in case of a collision, is attained according to the invention by providing that at least the wall sections oriented predominantly in the longitudinal direction of the vehicle exhibit a predetermined buckling resistance which, in case of an accident, is exceeded, utilizing the foam material for additional energy absorption when the wall sections are buckling.
A saving in weight and a simple, economical design of blocking or control elements are obtained according to preferred embodiments of the invention wherein the foam material also serves as a gasket in the contact zone of adjustable air control flaps.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawing which shows, for purposes of illustration only, an embodiment construction in accordance with the present invention.